|Peter Jenkins||29/11/2013 10:54:05|
|1389 forum posts|
Hi. Having pretty much taught myself to fly aerobatics, I thought it would be helpful for others who either want to start flying aerobatics or to improve their aerobatic flying to have a thread to which they could turn for help and advice. RCM&E is currently carrying a series written by Shahid Banglawala on how to fly the Clubman Schedule and while Shahid invites you to email him any questions it may be that some folks would rather use a forum such as this one to discuss the issues they are having with achieving the desired aerobatic shapes in the sky! Many of the photos in Shahid’s articles show quite humble airframes – the pilot remains the biggest factor in achieving a good aerobatic performance.
While there are specialist forum for aerobatic pilots, I thought there might be a large number of users of this forum who would find this thread useful and that we could build up a body of information that you could dip into as you progressed. Eventually, you might decide to graduate to other more specialist forum but I would hope that you’d keep an eye on this one.
One of the key barriers to getting into aerobatics is the fear that it will be very expensive. The reality is that many sport aerobatic models can be made to perform a great deal better than you would think by careful trimming. You can, of course, buy a 50 size aerobat and you will be amazed at how well they fly – but that’s not necessary. I started with a Wot4, which I still have and still fly and it’s great fun. Specialist aerobatic aircraft don’t have to cost much more than the standard ARTF sports model. Alternatively, thanks to the resurgence in interest in vintage aerobatic aircraft under the UK CAA there is an increasing number of plans being dusted off and brought back into use or else you can buy something like Ripmax’s Bullet if you prefer the ARTF route.
So, I hope we’ll get lots of contributions from those seeking and those offering information on getting into aerobatics.
|Rich too||29/11/2013 11:09:08|
3057 forum posts
Absolutely, and I recently purchased a sim for that purpose (it even has a training mode for prop hanging - it is my ambition to be able to prop hang!) - and I'm glad I did, i have crashed so many times on the sim!!
everyone should have one.
|fly boy3||29/11/2013 12:03:30|
3637 forum posts
Yep, I'm interested in trimming before starting. Most of my models tend to yaw for a start in big loops, or is it me. LoL Cheers
|Steve Colman||29/11/2013 12:10:34|
744 forum posts
I'm on board.
This past summer I've been trying to fly my models in a much more disciplined manner. I agree absolutely about careful trimming and set up; makes a world of difference no matter the type of model.
I taught myself to fly a few years ago, and like Peter, I've taught (trying to teach) myself aerobatics. I distinguish flying aerobatics in a disciplined way as opposed to just bashing the sticks around from corner to corner. It certainly isn't easy without an instructor and it does take some effort, determination and practice.
I currently fly an Acromaster set up between 3D and general acros as my go to plane. An E-flite Leader 480 which is still at the flight trimming/set up stage. Lastly, I have a trusty Calmato ST1400 with which I'm trying to fly pretty much as a pattern ship.
Unfortunately, due to a combination of poor weather, a myriad of other things and a little health scare, I've not been able to get out to fly for a while. So, I'm trying to learn about the diagrams/symbols for the various manouvres.
In the new year I may buy an entry level pattern model along the lines of a Sebart Angel S30e/S50e.
|David Davis||29/11/2013 12:18:07|
3590 forum posts
I'd be interested in improving my aerobatics but I'm not interested in participating in competition, as much as anything else because of the transport costs of getting to events these days. My main interest is in scale and I'd like to improve my rolls which are awfully barrelly and my landings which I cannot carry out consistently smoothly in the place where I want to land the model.
There used to some instructions on this site about flying the roll. It all looked a bit complicated. Perhaps I should have printed them off.
Having said that I loved flying my DSM Smart Move until I crashed it through getting disorientated and the best model I've ever had for doing rolls was my Chris Olsen Uproar which dates from 1958!
|karl grey||29/11/2013 14:39:10|
100 forum posts
Count me in.
Been trying to get to grips with aerobatics after passing my 'A' and after winning this years novice aerobatic comp at my flying club I am aiming at improving and moving up to clubman level.
Having fun with my wot4 practicing new moves and currently trying to master a slow roll. I do have a 90 size yak 54 in my hangar but still in the trimming setup stages but does fly well.
Just got one off Steve Dunnings Elation Models Rapture 50 kits to build as a pattern flyer and hope to make a start on that very soon.
|1106 forum posts|
An excellent idea and I will certainly be following this thread.
I've been flying for a year and put in quite a lot of hours this season and decided that whilst I don't need to prop hang (not yet anyway), I do want to have a bit of discipline and structure to my flying. I regularly tap more experienced flyers for help and have collected anything and everything I can find off the web but I still need more. I hope that Shahid's series doesn't suddenly go quiet like his video series - stops when it gets interesting and no actual flying demonstrations.
There are some very helpful pilots at our club but I think modesty seems to prevent them from really explaining the details - they don't seem comfortable when in "training mode".
Edited By Masher on 29/11/2013 15:02:00
|john melia 1||29/11/2013 15:49:28|
1770 forum posts
yep most definately interested , can do a range of aerobatics on phoenix but its just not the same at the field
|John Laverick||29/11/2013 16:30:59|
230 forum posts
Yup, I'm in
Like many I taught myself to fly and can do some wonderful stuff on the Phoenix, but like John says it most definitely is not the same at the field. Doesn't cost nowt to crash on the Phoenix!!!
|686 forum posts|
|Colin Carpenter||29/11/2013 17:32:53|
|621 forum posts|
Hi. Yes I too would be interested. I am trying to fly aerobatics with my Acrowot foam e but can`t manage a nice spin yet as it just dives with large rudder input. Rolls ,loops inverted (very high ! ) easy enough. Nearly finished a Hobbyking Rainbow F3A which I hope will help me improve.
More tips please.
|Bob Cotsford||29/11/2013 17:48:52|
8255 forum posts
I'm in, I find I struggle with cross winds carrying the model towards or away from the flightline with loops ending up as helix traveling across the field, losing rudder coordination on consecutive rolls, comical attempts at rolling circles - I blame my thumbs getting old
|Paul Marsh||29/11/2013 17:48:56|
3845 forum posts
I don't need practice...
|Peter Jenkins||29/11/2013 18:18:43|
|1389 forum posts|
Well, that’s an encouraging response! I should state right here that I can’t do 3D so I’d be looking to someone to chime in to help folks with that aspect. I do fly traditional aerobatics, or precision aerobatics as it is sometimes called. What differentiates these two styles is the way the aircraft is set up. However, that’s some way down the track.
As FB3 and Steve Colman have correctly identified, the first thing is trimming your model. So, let’s start there. Well, let’s start right at the servos first. The best way to ensure that you are making full use of the power and resolution of your servos is to spend a little time on setting them up correctly. By that I mean setting up the linkages to be as correct as possible.
Here’s one way. You start by looking at what you want to produce in the way of movement on your control surface. If you are intending to fly traditional, or precision, aerobatics then you do not need vast amounts of throw. For 3D, you do so if you want to have an airframe that does both you will need to make some compromises on performance. If you focus on just one discipline then you can optimise for that and get a better outcome. At the end of the day, the pilot’s skill will be the dominant factor in achieving the desired result but the right aeroplane, correctly set up don’t half help!
So, back to the servos. When you mounted your servos did you set the sub trim to 0 and then place the servo arm on (Futaba allows you to adjust the horn position in 4 steps) so that you get the servo arm at 90 deg to the servo centreline. Only use the sub trim then for fine adjustments. This prevents problems of having oodles of sub trim wound in to get the servo arm centred which could cause difficulty with non linear movement at the extremes of servo travel. Does everyone agree with this?
Next, think about how the servo generates its turning power or torque usually expressed as either Kg.cm (European) or oz in (US or imperial). The closer in to the servo shaft you connect your pushrod, the greater the power of the servo. The other end of the connection to the flying surface is then used to achieve the desired movement. Always start with 100%, or even the full 120%, of servo movement to produce the maximum control surface movement you want. What this does is reduces the effect of any backlash, or slop, in servo gears, and maximises the servo’s power. Use the Tx ATV to fine tune your set up. You also do not want to have oversize holes for your pushrod to rattle around in as you are introducing more unnecessary slop into the control run. Avoid Z bends to terminate your pushrods – yes they are quick way of connecting up but pushing them in enlarges the servo arm or control horn hole – leading to more slop! A simple 90 deg bend with a swing keeper is the way to go or else use the correct size quick link to ensure a solid slop free linkage.
For trad aeros, you’ll find that 10 deg to 15 deg is all you’ll need. That’s not much movement but it’s enough when you have the CG in the right place. So the rule is mount your pushrod as close in to the servo shaft as possible and position the pushrod in the appropriate hole on the control surface horn to give you the desired movement. Why use degrees and not mm or inches of movement? Depends on how long (measured along the direction of flight not spanwise – if you see what I mean) your control surface is how much movement you need to measure at its end. Measured in degrees it’s the same for long or short surfaces. OK but how to convert the degrees into movement at the trailing edge of the control surface. If we call the control surface length L and the movement we want M, and the angle is A then the movement we want is:
M = L x sinA (where A is in degrees)
Sin 10 = 0.17
Sin 15 = 0.26
Sin 20 = 0.34
So M = L x 01.7 (for 10 deg) and if you have a control surface of 25 mm
M = 25 x 0.17 = 4.25 mm
It’s not much movement, is it! You can, of course, have more movement and set up your low rates to give you this very small movement or else use exponential to give you the same effect over quite a lot of stick movement depending on the amount of expo you use.
For 3D, you’ll want up to 45 degs of movement each way on a huge control surface. You will probably see that there is an inherent problem with having an aeroplane set up to do both disciplines – you have to trade off servo power (or buy more powerful servos) to avoid blowback and give you the speed of movement required on a 3D surface. Not that it can’t be done, just that you have to compromise.
OK. That’s enough for the first bit. Any comments gratefully received.
|1106 forum posts|
Peter, this is a good start with plenty of detail and explanation - pitched just right for me!
I don't know if you want a million questions, well you'll get 'em anyway, but regarding the bit
"You can, of course, have more movement and set up your low rates to give you this very small movement or else use exponential to give you the same effect over quite a lot of stick movement depending on the amount of expo you use."
I am doing this method with 3 sets of rates and about 30% expo. Is there a preferred method or do you just choose the method you like best?
|Peter Jenkins||29/11/2013 20:32:50|
|1389 forum posts|
Masher, I think your solution seems fine. The one thing to bear in mind is that while initial set up is very important, after that it's a matter of tweaking things until you get the desired effect. More on that later.
|Mark Allen 1||29/11/2013 21:27:30|
|10 forum posts|
My flying has improved since I realised i was using too much surface control which I put down to lone flying and not knowing any better. It's surprising how little throw is required to fly clubman and bmfa manouvers.
|john melia 1||29/11/2013 21:34:57|
1770 forum posts
what a great thread this is turning out to be , hopefully I'll be putting some of it into practise tomorrow . Well done peter for starting it off
944 forum posts
I'll be watching this one with interest.
Unfortunately I also fly a funflier with +/- 45 deg of throw which means on anything set up for normal aerobatics I keep running out of control authority. Basically I find it difficult to adjust between one type and another.
|Peter Jenkins||29/11/2013 22:56:10|
|1389 forum posts|
Flying lots of different types of aircraft is good fun, but I found out as you have, that when you have to keep changing the way to fly several times during your day at the patch, it is difficult to get good at any one thing. I found that my flying began to improve once I focused on flying just one aircraft. I got so used to it I began to get quite good at flying consistently - not as well as I would have liked but a lot better than I had been achieving. I happened to be preparing for my B certificate so stuck with it and flew just my Wot 4 for 5 months. It paid off as I got my B and I found that I could adapt to fly my other aircraft very much better than I used to. I also found that I could now fly in weather up to a 20 mph 90 deg cross wind (not to be recommended by the way) as well as cutting down on my crashes. I thought that was a fair return to sticking with one aeroplane for 5 months. Where I see people come to the patch with 3 quite different aircraft and they are struggling to fly half decently, I recommend that they just fly one until their competence improves significantly. Sadly, most of them ignore that advice and continue to struggle to improve. Worth thinking about.
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